Electromagnetic relay



July 12, 1966 w. F. AUER 3,260,817

ELECTROMAGNETIC RELAY Filed Oct. 23, 1965 2 Sheets-$heet 1 INVENTOR. WILLIAM F. AUER ATTORNEYS July 12, 1966 w. F. AUER 3,260,817

ELECTROMAGNETIC RELAY FIG. 3

INVENTOR.

WILLIAM F. AUER ATTORNEYS I gravitational forces.

United States Patent 3,260,817 ELECTROMAGNETIC RELAY William F. Auer, Des Plaines, 'Ill., assignor to Con ar Electric Company, Chicago, Ill., a corporation of Illinois Filed Oct. 23, 1963, Ser. No. 318,311 6 Claims. (or. zoo-s7) This invention relates to an electromagnetic relay, and more particularly to a minute electromagnetic relay of so-called micro-miniature size.

Relays of the type to which the present invention is directed are commonly called micro-miniature relays in that their over-all dimensions are extremely small for relays, being in the order of one-half inch in any given direction. Since such relays are often employed in missiles and other devices subjected to extreme environmental conditions, the relays must be of substantial and rugged construction with the ability to resist vibrations and changing Moreover, such relays, because of their small size, are limited as to the size of components that can be employed therein, and likewise, are limited as to the number of components that can be employed therein.

' Accordingly, an object of the present invention is a new and improved electromagnetic relay of the microminiature size capable of withstanding vibrations and also capable of performing additional functions, which formerly required a number of additional elements, due to a novel relationship between a supporting structure and the electromagnetic coil assembly.

More specifically, electromagnetic relays commonly have employed adjustment devices for an armature return spring that have included a threaded adjustment screw. A threaded-screw type of spring adjustment requires the provision of an extra screw element within a small relay; it is also subject to losing its adjustment setting as a result of turning when vibrations are encountered. In accordance with another object of the invention, the armature return spring of the present electromagnetic relay has its biasing force adjusted by the bending of a projecting lug or finger of the supporting structure to bear against the armature return spring, the projecting lug not being subject to losing its adjustment due to vibration.

Heretofore, some electromagnetic relays have been provided with a threaded screw serving as an armature stop for limiting the amount of movement of the armature under the influence of an armature return spring. Such a threaded screw type of adjustment requires additional elements within a small relay, and the threaded screw is still subject to turning under vibrational forces. Accordingly, another object of the present invention is the limiting of the rotation of the armature by a portion of the supporting structure which is not subject to losing its adjustment due to vibrations, and which does not require a separate element to perform this function.

Specifically, under the present invention, and in accordance with a further object thereof, a simple supporting structural element performs the multiple functions of supporting an operating assembly, controlling the operating force of the armature return spring, limiting the return movement of the armature, and providing a ledge to receive a cover for the relay.

Vibrational forces have heretofore affected the connection between the fine wires of the coil and the terminal connector on the base. A terminal wire is of substantially more rigid construction than the fine coil wire, and vibration or twisting of a terminal conductor can cause breaking of the fine coil wire at the point of connection with the fine coil wire. In accordance with an object of the present invention, the fine coil wire of the coil is connected to a piece of metallic foil which does not tend to 7 3,260,817 Patented July 12, 1966 vibrate with the terminal connectors to which it is attached, and cause a breaking at its point of connection with the coil wire due to vibration.

In view of the extremely small size of a micro-miniature relay, it is difficult to assure that the armature is correctly mounted, so that when the armature is attracted, it moves into flush engagement with the pole faces. Heretofore, the armature bearings and supporting structure have had a definite fixed relationship prior to an operation of the armature. Accordingly, a further object of the present invention is to mount the armature for flush engagement with the pole pieces, by means of armature bearings capable of being fixedly secured relative to their supports in a position and at a time when the armature is in flush engagement with the pole faces of the pole pieces.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to he the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appendedclaims.

In the drawings:

FIG. 1 is a perspective view showing the electromagnetic relay constructed in accordance with a preferred embodiment of the invention;

FIG. 2 is a perspective view showing the electromagnetic relay encapsulated within a cover;

FIG. 3 is a plan view showing the electromagnetic relay of FIG. 1; and

FIG. 4 is a sectional view showing the contact assemblies mounted on the base and a portion of the contact actuating arms therefor.

Referring now to the drawings, and more particularly to FIG. 2, the electromagnetic relay 10 is shown in its encapsulated state wherein its operating instrumentalities are sealed from the environmental elements by a cover 11 suitably fastened to a base 12 such as by soldering or by a suitable adhesive material or by cold pressure welding. Projecting downwardly from the base 12 are terminal connectors or hooks 14 whereby electrical connections can be readily made to the operating instrumentalities of the electromagnetic relay 10 within the cover 11. The electromagnetic relay to which the present invention is directed is of the micro-miniature size; its over-all dimensions are substantially under one inch in any given direction and more closely approximate one-half of an inch in at least two of the three dimensions. While the present invention is not to be construed as limited to a microminiature relay, .it is particularly adapted to micro-miniature relays wherein the achievement of a multiplicity of functions from a single element helps reduce the size of the relay.

The coverll has its lower edge seated on a shelf or shoulder 15 formed about the base 12 by an encircling rim portion 18, FIG. 1, of a supporting means or element 20. The supporting element 20 comprises the rim portion 18, which extends about the entire peripheral edge of the base 12, and a pair of opposed upstanding supports or supporting portions 22 which are disposed beneath the opposed pole pieces 24 and 25. A coil 27 for the relay 10 extends between and is staked to the pole pieces 24, 25. The supporting legs 22 are soldered or otherwise suitably attached to each of the pole pieces 24 and 25, and thereby hold the pole pieces in spaced relationship to the base 12.

The leaf spring 3-2 has an offset portion 33 secured by soldering or in other conventional manner. In addition to the upstanding supporting legs 22, the supporting element 20 has integrally formed thereon an upstanding lug or finger 30 having an upper end 31 disposed to bear against a leaf spring 3-2. The upstanding lug 30 is of relatively small dimensions, and is easily bent, relative to its lower end portion where the lug 30 joins the rim 18, by the application of a force on the upper end 31. The bending force can be applied as by pressing against end 31 with a screw driver. Thus, the spring 32 can be bent inwardly to have its forward, curved-end portion 34 exert a greater biasing force on a pivoted armature 35. The finger 30, of course, can be bent outwardly to reduce the deflection of the leaf spring 32 and thereby lessen the amount of force exerted by the leaf spring 32 on the armature 35. This lug 31 is bent to assume a permanent set or deflection and hence is not subject to being vibrated loose as would a typical threaded adjustment screw.

The leaf spring 32 has an offset portion 33 secured by welding to the pole piece 24, with the main body portion thereof spaced from the pole piece 24, FIG. 3. The end 34 of the leaf spring 32 engages the armature 35 and tends to rotate the armature 35 in a clockwise direction (FIGS. 1 and 3) about the armature pivot pin 38 to bring a tapered end portion 39 of the armature 35 into engagement with an armature stop 40. The armature stop 41) is another upstanding lug or finger-like element on the relay supporting element 20 and is like the spring adjusting lug 30 in that it can be permanently bent or deformed to assume a number of variable positions. Thus, the position to which the stop 40 is bent determines how far the armature 35 can be rotated in a clockwise direction. The amount of rotation of the armature 35 determines the armature gap between the armature 35 and the inwardly turned legs 44 and 45 of the pole pieces 24 and 25, respectively.

As best seen in FIG. 3, the inwardly turned legs of the pole pieces 24 and 25 have tapered surfaces forming pole faces 46 and 47, respectively, which faces are approximately parallel to the opposite surfaces of the armature 35. The tapered surfaces 46 and 47 of the pole pieces 24 and 25 are so tapered that when the opposite portions of the armature 35 are attracted thereto the opposing portions will be in flush engagement with the pole faces 46 and 47. The amount of armature gap and travel are quite small and are shown in exaggerated form in FIG. 3.

The armature 35 is pivoted centrally about a fixed pivot pin 38 which extends through apertures in a pair of circular bearings 50. The bearings 50 are each welded or otherwise suitably secured to a respectively associated armature support 54. Each armature support 54 has two legs 55 and 56 welded or otherwise suitably secured to the pole pieces 24 and 25, respectively.

Since the armature 35 is a small element and its movement is over a small distance, the proper positioning of the armature 35 against the pole faces 45 and 46 is difiicult to obtain with prior art armature and bearing supports wherein the bearings and supports are fixedly mounted prior to operation of the relay. Under the present invention, the armature supports 54 are first secured to the side edges of the legs 44 and 45 of the respective pole pieces 24 and 25 by welding or other suitable means. With the position of the supports 54 fixed, the armature 35 and pivot pin 33 carrying the bearings 50 are roughly positioned in place with the pivot pin 38 and an outwardly projecting collar 57 on the bearings 50 extending into generally rectangular openings formed by a projection 58, and opposing leg 56 of the support 54. The rectangular openings are relatively large compared to the pivot pin 38 and bearing collars 57 so that they can be freely positioned therein.

As thus assembled, the coil 27 is energized to generate a magnetic field acting across the air gap to attract the armature 35 against the pole faces 46 and 47. At this time, the washer-like bearings 50 are welded to the supports 54. Since the bearings 50 are secured in position when the armature 35 is magnetically attracted to seat flush against the pole faces 46 and 47, the bearings 50 and the seats 57 retain these positions; in subsequent operations, the armature 35 is always in proper position to move into flush engagement with the pole faces 46 and 47.

As thus assembled, the armature 35 is journaled in the bearings 56, which are secured to the bearing supports 54 on the pole pieces 24 and 25, that carry the coil 27. These elements, all being secured together, constitute the operating assembly for the contact assemblies 60 and 72 which are on the base 12, as will hereinafter be explained.

For the purpose of operating contact assembly 60 and 72, on the base 12, the armature 35 has welded, soldered or otherwise suitably attached thereto a pair of opposed contact actuating arms 61 and 62, FIG. 3. As seen in FIG. 1, the contact actuating arm 62 has an upper vertical portion 63 welded to the end 39 of the armature 35, with a laterally extending leg portion 63 terminating in a non-conducting ball 64 of glass or other insulating material. The contact actuating arm 61 is similarly formed and attached to the opposite end of the armature 35. As best seen in FIGS. 3 and 4, the contact actuating arm 62 rotates in a counterclockwise direction about the pivot pin 38, when the armature 35 is attracted to the pole pieces 45 and 46. Movement of the insulator ball 64 against a contact element 65 causes the contact element to rotate about an upstanding post or portion 67 of one of the terminal connectors 14. A leaf spring 68 attached to another post 67 biases contact element 65 against a fixed contact element 70.

As the insulator ball 64 of the contact actuating arm 62 engages the outer end of the contact element 65 and pivots the contact 65 counterclockwise about the post 67, the normally closed contact assembly is opened, since the contact element 65 is no longer in engagement with the fixed contact element 70. The fixed contact element 70 is a flexible element fixedly mounted on an arm 71, which is secured to and extends from a post 67 on a terminal connector 14.

The contact actuator arm 61 is operable to rotate a contact element 72 into engagement with a fixed contact element 73 to afford a set of contacts that remain closed so long as the armature 35 is held against the pole pieces 45 and 46. The contact element 72 is pivotally mounted on a post 67 and is flexed to return to the position shown in FIG. 4, wherein the contact arm 72 rests against a stop element 75 secured to a post 67. Thus, when the armature 35 is pivoted against the pole pieces 45 and 46, the actuating arms 61 and 62 serve to close the contact pair 74, and open the contact pair 60, respectively.

The base 12 is a metallic element having eight circular apertures therein through which extend the upstanding posts 67 of the connectors 14. Connectors 14 are sealed into and insulated from the base by insulators (FIG. 1).

Heretofore the fine wire leads from a magnet coil such as the coil 27 have been attached directly to the appropriate post 67 for connections to an electrical source of energization for the coil. Since the coil is of such extremely small size, and since the coil wire is of a correspondingly small size, considerable difliculty and painstaking work are needed to attach the fine wire leads to the post 67. In lieu of the fine wire connections of the prior art, the present invention employs relatively wide metallic foil connections and 86, FIG. 4, which extend from the coil 27, in lieu of the fine wires, to the post 67. The foil 86 extends straight downwardly and is connected to the post 67 directly therebeneath, whereas the foil connector 85 extends beneath the contact elements 65 and 72 to a post 67 on the opposite side of the base 12. In order to insulate the connecting foil 85 from the base 12 and the contact arms 65 and 72, the foil 85 is sandwiched between a pair of plastic insulator sheets 90. Thus, the metallic foil serves as a convenient groans for attaching the coil leads to terminals in the ase.

From the foregoing, it is believed to be apparent that the present relay provides a unique and simple supporting element for the operating portion of the relay which not only serves to support the operating assembly 59, but which also has portions thereof effective to control the force of the armature return spring, and adapted to limit the movement of the armature under the force of the armature return spring. Likewise, it should be apparent that the adjustable fingers or lugs and are not subject to being loosened or displaced as the result of vibration, and constitute simple but rugged means for accomplishing the desired purposes.

Hence, while preferred embodiments of the invention have been described and illustrated, it is to be understood that they are capable of variation and modification and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. In an electromagnetic relay comprising a base, an operating assembly including an operating coil, pole pieces and armature pivotally mounted for movement into contact with said pole pieces, contact means on the base operated by said armature, terminal connectors rigidly secured to said base and leading to the opposite side of said base, said operating coil having wire wound thereon, said coil wire being fragile and of substantially less thickness than said terminal connectors, and metallic foil means electrically interconnecting a coil wire to a terminal connector to facilitate connection between said coil wire and said terminal connector and to prevent breaking of said coil wire at said terminal connector with vibrations.

2. In an electromagnetic relay comprising a base, an operating assembly including an operating coil, pole pieces and armature pivotally mounted for movement relative to said pole pieces, contact means on the base operable by said armature, pin terminal connectors of a first diameter rigidly secured to said base and leading to the opposite side of said base, said operating coil having wire wound thereon, said wire being of a substantially smaller diameter than the diameter of said terminal connectors, and metallic foil electrically interconnecting said coil wire to one of said terminal connectors to facilitate connection between said coil wire and said terminal connector.

3. In an electromagnetic relay having a coil and pole piece assembly with a centrally pivoted armature held by a supporting means and pivotally movable between an initial position and an energized position; an armature return spring engaging said armature and biasing said armature toward said initial position; a base means having a plurality of contacts thereon movable by said armature; a cover means removably secured to said base means to cover said armature and said coil and said pole piece assembly; a supporting assembly on said base means and supporting said coil and pole piece assembly, in spaced relationship to said base, said supporting means having a first integrally formed finger portion thereon bendable into engagement with said armature return spring, and a second bendable finger bendable into the path of rotation of said armature means to limit rotation of said armature to a predetermined amount, said supporting means extending about the base means and near the periphery thereof, to form with said base a seat for said cover means for said relay.

4. The electromagnetic relay of claim 3 including fixed terminal means on said base and metallic foil connecting means extending between said terminal means and said coil.

5. In an electromagnetic relay: a base; a pair of pole pieces secured to said supporting means and supported thereby in spaced relation to said base, said pole pieces having inwardly directed portions, separated by an air gap, with pole faces thereon; an electromagnet coil supported by said pole pieces; a pair of bearing supports, extending across said air gap and secured to said inwardly directed portions of said pole pieces, each having a centrally located opening intermediate saidinwardly extending portions of said pole pieces, said openings being generally aligned with each other; an armature of magnetic material; means affording a pair of coaxial pivot pins extending from opposite sides of said armature into said central openings in said bearing supports to mount said armature for rotational movement, in response to energization of said electromagnet coil between a first position in which said armature is disengaged from said pole faces and a second position in which said armature engages both pole faces and bridges said air gap, said pivot pins being substantially smaller than said openings; and a pair of individual bearing members, each closely encompassing one of said pivot pins and rigidly aifixed to one of said bearing supports, for maintaining said armature in accurately aligned position for consistent engagement with both of said pole faces, said bearing members being afiixed to said bearing supports while said armature is maintained in engagement with both pole faces by energization of said electromagnet coil to assure precision alignment of said armature with respect to said pole faces.

6. The electromagnetic relay of claim 5 including fixed terminal means on said base and metallic foil connecting means extending between said terminal means and said coil.

References Cited' by the Examiner UNITED STATES PATENTS 3,104,295 9/1963 Bender et a1 20087 3,147,349 9/ 1964 Welch et al 200-87 3,138,677 6/1964 Adams 200104 3,154,653 10/1964 Rowell 200-87 3,161,808 12/1964 Tromholt 200 -87 KATHLEEN H. CLAFFY, Primary Examiner.

BERNARD A. GILHEANY, Examiner.

B. DOBECK, Assistant Examiner. 

1. IN AN ELECTROMAGNETIC RELAY COMPRISING A BASE, AN OPERATING ASSEMBLY INCLUDING AN OPERATING COIL, POLE PIECES AND ARMATURE PIVOTALLY MOUNTED FOR MOVEMENT INTO CONTACT WITH SAID POLE PIECES, CONTACT MEANS ON THE BASE OPERATED BY SAID ARMATURE, TERMINAL CONNECTORS RIGIDLY SECURED TO SAID BASE AND LEADING TO THE OPPOSITE SIDE OF SAID BASE, SAID OPERATING COIL HAVING WIRE WOUND THEREON, SAID COIL WIRE BEING FRAGIBLE AND OF SUBSTANTIALLY LESS THICKNESS THAN SAID TERMINAL CONNECTORS, AND METALLIC FOIL MEANS ELECTRICALLY INTERCONNECTING A COIL WIRE TO A TERMINAL CONNECTOR TO FACILITATE CONNECTION BETWEEN SAID COIL WIRE AND SAID TERMINAL CONNECTOR AND TO PREVENT BREAKING OF SAID COIL WIRE AT SAID TERMINAL CONNECTOR WITH VIBRATIONS. 